On-Demand Activation of Radio Frequency Identification (RFID) Tag

ABSTRACT

In aspects of on-demand RFID tag activation, an RFID tag is configured so as to enable a person to activate the RFID tag if or when the person wishes. An RFID tag includes an integrated circuit (IC), an antenna coupled to the IC, activation circuitry, and a detachable disable tab. For an example implementation, the RFID tag is in an active state if the IC is capable of responding to an interrogation signal and is in an inactive state if the IC is incapable of responding to an interrogation signal. The activation circuitry is configured to establish the inactive state if the disable tab is attached to the RFID tag or to establish the active state if the disable tab is detached from the RFID tag. The disable tab, if attached to the RFID tag, may impose a short-circuit linkage against the activation circuitry to prevent operation of the tag.

RELATED APPLICATION

This application is a continuation of and claims priority to U.S. patentapplication Ser. No. 14/740,302 filed Jun. 16, 2015 entitled “On-DemandActivation of Radio Frequency Identification (RFID) Tag”, the disclosureof which is incorporated by reference herein in its entirety.

BACKGROUND

The acronym RFID is taken from the term “Radio-FrequencyIdentification.” With RFID, small electronic tags are programmed withidentifying data or other information. RIFD tags are capable ofwirelessly providing information using a radio frequency (RF)communication channel. In one example usage scenario, an inventoryproduct code such as a stock-keeping unit (SKU) may be stored by an RFIDtag to track inventory in a warehouse or to facilitate customercheck-out in a store. RFID tags can therefore be used instead of barcodes. Bar codes are visual identifiers that necessitate line-of-sightto be acquired by a bar code reader. RFID tags, in contrast, do notrequire a line-of-sight view for RFID readers to acquire informationthat is stored on the RFID tags.

For responsive RFID tags, an RFID reader transmits an interrogationsignal that effectively serves as a broadcast message requesting RFIDtags that are in range to return information that the RFID tags havestored. If multiple RFID tags are in range, then an RFID reader may beinundated with multiple responses from multiple RFID tags. Multipleresponses confuse the RFID reader such that at least some of theresponses are not correctly received or not correctly interpreted. Themore RFID tags that are in range of an interrogation signal that istransmitted by an RFID reader, the greater the likelihood that responsessent by the RFID tags will create mutual interference due to collidingsignals and the larger the probability that the RFID reader will fail tocorrectly receive or will fail to correctly interpret all of theresponses sent by the RFID tags.

As production costs have decreased, RFID tags have become more common.Cheaper RFID tags may become ubiquitous in the coming years forinventory purposes as well as for many other usage scenarios.Consequently, problems with reading RFID tags due to collisions ofmultiple responsive signals will become increasingly prevalent. Thefrequency of occurrence of tag reading collisions can be ameliorated, tosome degree, using purely electronic approaches. However, such purelyelectronic approaches increase the cost and complexity of RFID readersor RFID tags, and purely electronic approaches may not be whollyeffective or may not be universally applicable across differentmanufacturers or RFID platforms.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of on-demand activation of RFID tags and person-centricactivation of RFID tags are described with reference to the followingFIGS. The same numbers may be used throughout to reference like featuresor components that are shown in the FIGS.:

FIG. 1 illustrates an example RFID environment in which embodiments ofon-demand RFID tag activation or person-centric RFID tag activation canbe implemented.

FIG. 2 illustrates an example RFID tag with which embodiments ofon-demand RFID tag activation or person-centric RFID tag activation canbe implemented.

FIG. 3 illustrates an example RFID tag for implementations of on-demandRFID tag activation in accordance with one or more embodiments.

FIGS. 3-1, 3-2, and 3-3 are additional example RFID tags forimplementations of on-demand RFID tag activation in accordance with oneor more embodiments.

FIGS. 4 and 5 illustrate example methods for on-demand RFID tagactivation in accordance with one or more embodiments.

FIG. 6 illustrates an example RFID tag for implementations ofperson-centric RFID tag activation in accordance with one or moreembodiments.

FIGS. 6-1, 6-2, and 6-3 are additional example RFID tags forimplementations of person-centric RFID tag activation in accordance withone or more embodiments.

FIGS. 7 and 8 illustrate example methods for person-centric RFID tagactivation in accordance with one or more embodiments.

DETAILED DESCRIPTION

RFID tags generally are capable of wirelessly providing information inresponse to an interrogation signal that is received from an RFIDreader. If multiple RFID tags receive an interrogation signaltransmitted from an RFID reader, then multiple RFID tags send backresponses. The multiple responses can collide and confuse the RFIDreader, which causes at least some of the responses to be unread or tobe improperly interpreted. As noted above, there is some anti-tagcollision technology that attempts to induce order on multiple RFIDresponses, but with the drawback that the technology adds complexity andcost to at least the RFID readers.

Another problem created from a proliferation of RFID tags is that RFIDreaders are more active receiving, demodulating, and interpretingresponses from RFID tags, as well as any further processing of theinformation acquired from the received responses. These actions consumepower, which is limited in battery-powered portable devices. If RFIDtags are not usefully deployed but are susceptible to being read usingan interrogation signal, the limited battery power of RFID readers maybe consumed without fulfilling a useful purpose.

Yet another problem with existing RFID systems is that RFID tags areactive upon their manufacture. Consequently, RFID tags may beresponsively providing information that has no meaning or no realbenefit. For example, an RFID tag that is to be used for inventorymanagement may not yet be applied to an object, or an RFID tag that isto be used for tracking a package may be secured to a package that isnot yet in transit. As another example, an RFID tag that is tofacilitate safe consumption of a perishable food item may be created ormay be secured to packaging of the food item prior to when the packagingis opened or prior to when the food item is removed from refrigeration.As still another example, a medical implement, such as a bandage or asensor, that includes an RFID tag may provide RFID responses before themedical implement is placed on a person.

Embodiments of on-demand activation of RFID tags or person-centricactivation of RFID tags can reduce the number of RFID tags in the fieldthat are readable. Furthermore, embodiments can reduce the number ofRFID tags that are active prior to being usefully deployed. Aspectsdescribed herein may include, for example, those that enable manualactivation of an RFID tag by a user at a time of the user's choosing.Aspects described herein may further include, for example, those thatenable automatic activation based on proximity to (e.g., contact with)the skin of a person.

For one or more embodiments, with regard to on-demand activation of RFIDtags in particular, an RFID tag may be inactive until it is usefullydeployed as determined by a person. For example, an RFID tag with adisable tab attached thereto may be incapable of responding to aninterrogation signal until a person manually activates the RFID tag. AnRFID tag may be activated by physically detaching the disable tab fromthe RFID tag. Detaching a disable tab may remove a short-circuit linkagethat is coupled to an antenna lead of an RFID tag or that is coupled toan operability input of an integrated circuit of an RFID tag.Alternatively, an open circuit condition that is preventingfunctionality of an RFID tag may be eliminated by detaching a disabletab.

Upon activation, an RFID tag is enabled to respond to an interrogationsignal, which is received from an RFID reader, with at least someinformation. A response signal from an RFID tag may include, forinstance, an identification indication or an expiration date as at leastpart of the information. Alternatively, an RFID tag response may includea parameter derived from a sensor value obtained from a sensor that ison-board the RFID tag or a parameter derived from a time value (e.g.,elapsed time) obtained from a timer that is on-board the RFID tag.Examples of sensor values include a temperature value representative ofcurrent or average temperature, a weight value representative ofcontents remaining in a package, and so forth.

For one or more embodiments, with regard to person-centric activation ofRFID tags in particular, an RFID tag may be inactive until it isusefully deployed proximate to a person. For example, an RFID tag mayhave an open-circuit condition that is remedied by skin contact. Aportion of the skin completes a circuit of the RFID tag and renders theRFID tag active so that the RFID tag is capable of responding to aninterrogation signal. Alternatively, an RFID tag may include atemperature sensor that is adapted to measure a temperature of a personbased on skin contact. If a sensed temperature is within a rangeindicative of a person, then an integrated circuit of the RFID tagresponds to an interrogation signal; otherwise, the integrated circuitdoes not respond to a received interrogation signal.

Hence, upon activation based on skin proximity (e.g., skin contact), anRFID tag is configured to respond to an interrogation signal receivedfrom an RFID reader with at least some information. A response signalfrom an RFID tag may include, for instance, an identification of or atype of medication as at least part of the information. Alternatively,an RFID response may include a parameter derived from a sensor valueobtained from a sensor that is on-board the RFID tag or a parameterderived from a time value (e.g., elapsed time) obtained from a timerthat is on-board the RFID tag. Examples of sensor values include anelectrical signal value representative of cardiac or brain activity, atemperature value representative of a patient's body temperature, achemical indicator value representative of whether or a degree to whicha particular chemical is detected, and so forth.

Embodiments of on-demand activation of RFID tags and person-centricactivation of RFID tags are described herein below. General aspects aredescribed with reference to FIGS. 1 and 2. Specific aspects of on-demandactivation of RFID tags are described primarily, but not solely, withreference to FIGS. 3-5. Specific aspects of person-centric activation ofRFID tags are described primarily, but not solely, with reference toFIGS. 6-8. However, aspects of on-demand activation of RFID tags andaspects of person-centric activation of RFID tags are describedthroughout the present disclosure. Moreover, although aspects ofon-demand activation of RFID tags and aspects of person-centricactivation of RFID tags are described somewhat separately, embodimentsof on-demand activation of RFID tags and embodiments of person-centricactivation of RFID tags may also be implemented jointly. By way ofexample only, an RFID tag may have a timer that is started by detachinga disable tab, and the RFID tag may be placed in an active state bybeing positioned against skin. As another example, activation of an RFIDtag such that the RFID tag responds to interrogation signals may entailboth detachment of a disable tab and detection of a temperature that isabove a minimum body temperature or that is within a defined range ofbody temperatures.

Although features and concepts of on-demand RFID tag activation andperson-centric RFID tag activation can be implemented in any number ofdifferent apparatuses, systems, environments, and/or configurations,embodiments of on-demand RFID tag activation and person-centric RFID tagactivation are described in the context of the following example RFIDtags, apparatuses, systems, and methods.

FIG. 1 illustrates an example RFID environment 100 in which embodimentsof on-demand RFID tag activation or person-centric RFID tag activationcan be implemented. RFID environment 100 is a logical or block diagramof an example RFID system. As illustrated, example RFID environment 100includes a radio frequency identification (RFID) tag 102 having anintegrated circuit (IC) 104 and an antenna 106, an electronic device 108having an RFID reader 110, an interrogation signal 112, and a responsesignal 114. RFID reader 110 comprises at least a portion of electronicdevice 108. Examples of electronic devices 108 include an RFID readergun, a mobile phone, a smart watch, a notebook computer, retail securityscanning hardware, medical monitoring hardware, manufacturing orwarehouse or retail inventory tracking hardware, a refrigerator, or somecombination thereof.

For example embodiments, RFID reader 110 wirelessly transmits aninterrogation signal 112 to one or more in-range RFID tags, such as RFIDtag 102. RFID tag 102 receives interrogation signal 112, whicheffectively requests that RFID tag 102 provide information wirelessly. Arequest (not explicitly shown) of an interrogation signal 112 mayspecify particular information that is desired or may be asking forinformation generally. In response to receipt of the interrogationsignal 112, IC 104 formulates response signal 114, and RFID tag 102provides the response signal 114 wirelessly via antenna 106. RFID tag102 may provide response signal 114 via a wireless communication that issent over an air interface. A response signal 114 may be generated byRFID tag 102 as a version of a received interrogation signal 112 thatcomprises modulated RF backscatter off of antenna 106 of the RFID tag102 or a reflected encoded version of the received interrogation signal112. Additionally or alternatively, for a powered RFID tag 102, aresponse signal 114 may be transmitted using transmitter circuitry ofthe powered RFID tag 102.

RFID reader 110 receives wireless response signal 114 from RFID tag 102.Response signal 114 may include one or more pieces of information thatRFID tag 102 is storing, has obtained, is producing, and so forth.Examples of information that can be included in a response signal 114are an identification indication such as a code or an alphanumericvalue, a parameter derived from a sensor including a sensor value, aparameter derived from a timer including a time value, a descriptiveindication, or some combination thereof. Additional examples aredescribed herein below.

RFID systems may be realized using at least low frequency (LF), highfrequency (HF), or ultra-high frequency (UHF) radio waves. RFID systemsmay be passive or active. With active systems, RFID tags may include orotherwise have access to an independent power source, such as a battery.With passive systems, RFID tags harvest energy from an interrogationsignal to enable the RFID tags to reflect back a response signal.Although not explicitly shown in the associated drawing figures, an RFIDtag may include a capacitor or a small battery to temporarily collectand retain some of the energy harvested from an interrogation signal topower IC processing or sending of a response signal.

Alternative or hybrid RFID systems may also be implemented. Examples ofother RFID systems include, but are not limited to, a passive readeractive tag (PRAT) system that has a passive reader which receives radiosignals from active tags (e.g., battery operated transmit only tags), anactive reader passive tag (ARPT) system that has an active reader whichtransmits interrogation signals and also receives reply signals frompassive tags, an active reader active tag (ARAT) system that uses activetags awoken or prompted by an interrogation signal sent from an activereader, a powered but passive tag system that has a powered passive tag(e.g., a battery-assisted passive (BAP) tag) that uses stored charge ina battery or capacitor to power continuous or repeated sensor readingand processing but awaits receipt of an interrogation signal beforeproviding sensed values, or some combination thereof.

FIG. 2 illustrates an example RFID tag 102 with which embodiments ofon-demand RFID tag activation or person-centric RFID tag activation canbe implemented. RFID tag 102 of FIG. 2 is a schematic diagram of anexample RFID tag. For example embodiments, an RFID tag 102 may includean RFID substrate 202. Examples of an RFID substrate 202 are paper,plastic (e.g., flexible or rigid), wood, glass, ceramic, printed circuitboard (PCB), or some combination thereof. An RFID substrate 202 may forma backbone or a foundation or a framework of a supporting structure forRFID tag 102. Alternatively, an RFID substrate 202 may be attached to,encapsulated within, incorporated as part of, etc. a backbone or afoundation or a framework of a supporting structure for RFID tag 102.

As illustrated in the example RFID tag 102 of FIG. 2, RFID substrate 202includes or at least supports an IC 104 and an antenna 106. IC 104includes two antenna terminals 204: a first antenna terminal 204(1) anda second antenna terminal 204(2). Antenna 106 includes two ends 206: afirst antenna end 206(1) and a second antenna end 206(2). (The part ofantenna 106 that is located at the top left corner of RFID substrate 202may alternatively or additionally be considered second antenna end206(2) (not explicitly indicated).) One of first antenna end 206(1) orsecond antenna end 206(2) may be considered an antenna loop in, and theother may be considered an antenna loop out. First antenna terminal204(1) of IC 104 is coupled to first antenna end 206(1) of antenna 106,and second antenna terminal 204(2) of IC 104 is coupled to secondantenna end 206(2) of antenna 106. Antenna 106 enables IC 104 to receiveor send wireless signals for RFID tag 102.

IC 104 may be implemented using any of one or more processors (e.g., amicroprocessor, a controller, a computing core, or a combinationthereof) or processing systems with storage memory havingprocessor-executable instructions that are fixed, hardware-encoded,programmable, alterable, wirelessly-receivable, or a combinationthereof. IC 104 may be realized, by way of example but not limitation,as an application-specific integrated circuit (ASIC), afield-programmable gate array (FPGA), a complex programmable logicdevice (CPLD), an application-specific standard product (ASSP), a systemon-a-chip (SoC), a silicon-based processing unit, or some combinationthereof. Generally, an integrated circuit can be realized with hardwarealong with one or more of software, firmware, or fixed logic circuitrythat is implemented in connection with processing or control circuits.

RFID tag 102 may further include processor-accessible storage memory(not explicitly shown) that is integrated with or discrete from IC 104.Storage memory enables persistent storage of data andprocessor-executable instructions (e.g., software applications,programs, functions, hard-coded operations, or a combination thereof).Storage memory can include various implementations of random accessmemory (RAM), read only memory (ROM), flash memory, or other types ofstorage media in various memory device configurations. Although notspecifically indicated in FIG. 2, RFID tag 102 may further include aninterconnect (e.g., a bus or other data transfer mechanism with traces,wires, buffers, etc.) that couples components of RFID tag 102 to eachother. Although not depicted in FIG. 2, an RFID tag 102 may also includea power source, such as a single-use battery, a battery that isrechargeable by wire or wirelessly, a capacitor, a combination thereof,and so forth.

RFID tags may be produced in many different shapes, sizes, form factors,and materials. For example, RFID tags may be flat (i.e.,two-dimensional) or three-dimensional (e.g., having an appreciable depthin addition to height and width). RFID tags may be square, rectangular,circular, triangular, box-shaped, spherical, cylindrical, and forth.Furthermore, RFID tags may be, for instance, at least as small as agrain of rice or at least as big as several inches across. An RFIDsubstrate of an RFID tag may be adhered to another object, such as in ashipping or product label usage scenario; may be incorporated intoanother object, such as packaging material or a medical implement; maycomprise an object having another purpose, such as for storage orshipping; and so forth. For example, an RFID substrate, or an IC and anassociated antenna thereof, may form part of a cardboard shipping box ormay be adhered to an underside of a milk container. Alternatively, anRFID substrate, or an IC and an associated antenna thereof, may comprisea bandage. Moreover, an RFID tag may be exposed or visible, or an RFIDtag may be enclosed within or encapsulated by another material orobject.

FIG. 3 illustrates an example RFID tag 102(1) for implementations ofon-demand RFID tag activation in accordance with one or moreembodiments. As illustrated in logical or block diagram form, exampleRFID tag 102(1) includes an RFID substrate 202, an IC 104, an antenna106, activation circuitry 302, and a disable tab 304. IC 104 is coupledto antenna 106 or activation circuitry 302; antenna 106 is coupled to IC104 or activation circuitry 302; and activation circuitry 302 is coupledto IC 104 or antenna 106. Disable tab 304 may be included as part of ormay be separate from RFID substrate 202.

For example embodiments, disable tab 304 is detachably attached to RFIDtag 102(1). RFID tag 102(1) is in an inactive state if disable tab 304is attached, but RFID tag 102(1) is in an active state if disable tab304 is detached from RFID tag 102(1). Activation circuitry 302, based atleast partially on if disable tab 304 is attached to RFID tag 102(1),places RFID tag 102(1) in, or causes RFID tag 102(1) to be in, an activestate or an inactive state. With an active state, RFID tag 102(1) isresponsive to an interrogation signal. With an inactive state, RFID tag102(1) is not responsive to an interrogation signal. In operation, RFIDtag 102(1) may be manufactured to be in an inactive state due to thepresence of disable tab 304. To activate RFID tag 102(1) on-demand, aperson or end-user may detach disable tab 304. Detachment of disable tab304 (e.g., separation, tearing, removal, etc. of disable tab 304 fromRFID tag 102(1)) may be partial or may be complete. Detachment ofdisable tab 304 (e.g., dislocation, peeling back, withdrawal, etc. ofdisable tab 304 from RFID tag 102(1)) may be permanent or may be subjectto re-attachment to deactivate RFID tag 102(1).

For one or more example embodiments, antenna 106 is configured toreceive an interrogation signal (e.g., interrogation signal 112). IC 104is coupled to antenna 106. IC 104 is capable of processing andresponding to the interrogation signal if RFID tag 102(1) is in anactive state, and IC 104 is incapable of responding to the interrogationsignal if RFID tag 102(1) is in an inactive state. Disable tab 304 isdetachable from RFID tag 102(1). Activation circuitry 302 is configuredto establish the inactive state if disable tab 304 is attached to RFIDtag 102(1) or to establish the active state if disable tab 304 isdetached from RFID tag 102(1). Example implementations of activationcircuitry 302 are described below with particular reference to FIGS. 3-1and 3-2.

FIG. 3-1 depicts additional example RFID tag implementations foron-demand activation of RFID tags in accordance with one or moreembodiments. As illustrated, RFID tag 102(1)-1 is a schematic diagram ofan example RFID tag that is depicted as a medical implement.Specifically, RFID tag 102(1)-1 is shown as a bandage with centralizedprotective padding, which may include topical medicine, at least onesensor, and so forth. However, RFID tag 102(1)-1 may be realized asanother type of medical implement, such as a medical sensor, a label, asan inventory tracking mechanism, some combination thereof, and so forth.

For example embodiments, RFID tag 102(1)-1 includes (i) an RFIDsubstrate 202 (e.g., also of FIG. 2) having a first RFID substrate side202(1) and a second RFID substrate side 202(2) and (ii) a detachablyattached temporary adhesive protector 304-1. Opposite sides of the RFIDsubstrate 202 are shown as first RFID substrate side 202(1) and secondRFID substrate side 20(2). Certain components are shown on therespective RFID substrate sides to avoid visually obscuring relevantcomponents or interrelationships of the components. Although certaincomponents are shown with respect to a particular substrate side, one ormore of the components may be on a same side, may be distributed acrossthe two sides differently than is depicted, may be implemented fully orpartially within the substrate, some combination thereof, and so forth.

Second RFID substrate side 202(2) includes an antenna 106 having a firstantenna end 206(1) and a second antenna end 206(2). First RFID substrateside 202(1) includes an IC 104, at least one adhesive portion 310, atleast one circuit element 312 that is part of activation circuitry 302(e.g., of FIG. 3), a ground node 318, and a connective circuit element320. IC 104 includes a first antenna terminal 204(1), a second antennaterminal 204(2), and an operability input 316, as well as a terminal toground node 318. At least one circuit element 312 may include a firstcircuit element 312(1) and a second circuit element 312(2). As shown,first RFID substrate side 202(1) includes two adhesive portions 310, butmore or fewer may be included on either or both of first and second RFIDsubstrate sides 202(1) and 202(2).

Temporary adhesive protector 304-1 is an example implementation of adisable tab 304 (e.g., of FIG. 3). Temporary adhesive protector 304-1includes at least one conductive element 314 and is adapted to coveradhesive 310, at least until a person wishes to adhere RFID tag 102(1)-1to another object. Alternatively, a disable tab 304 may be attached toan RFID tag using a different mechanism than an adhesive, such as aperforated tear-able material, a break-away material, and so forth. Acircuit element 312 may comprise, for example, a pad, a connectivecircuit element, a one or two-dimensional conductive element, anelectrical contact, or some combination thereof. Operability input 316may comprise, for example, a reset input, a chip enable input, a standbyinput, or some combination thereof. Connective circuit element 320 maycomprise, for example, a conductive material connecting two or moreother circuit elements, a trace, a lead line, a wire, a portion of abus, or some combination thereof.

In example operative embodiments, first antenna end 206(1) is coupled tofirst antenna terminal 204(1) of IC 104, and second antenna end 206(2)is coupled to second antenna terminal 204(2) of IC 104. First circuitelement 312(1) is coupled (e.g., via connective circuit element 320) tooperability input 316 of IC 104. Second circuit element 312(2) iscoupled to ground node 318. For an inactive state of RFID tag 102(1)-1in which IC 104 is incapable of responding to an interrogation signal112 (e.g., of FIG. 1), temporary adhesive protector 304-1 is flippedover and positioned (i) such that temporary adhesive protector 304-1covers adhesive portion 310 (e.g., adhesive portion 310 on the left sideof first RFID substrate side 202(1) of FIG. 3-1) and (ii) such thatconductive element 314 contacts first circuit element 312(1) and secondcircuit element 312(2).

If temporary adhesive protector 304-1 is attached to RFID tag 102(1)-1,a short-circuit condition is established between first circuit element312(1) and second circuit element 312(2) with a short-circuit linkagecreated by conductive element 314. This short-circuit condition couplesoperability input 316 of IC 104 to ground node 318, which disables IC104 in this implementation. Even if an interrogation signal is receivedby RFID tag 102(1)-1 via antenna 106, IC 104 is incapable of respondingto the interrogation signal. If a person is ready to activate RFID tag102(1)-1, the person may detach temporary adhesive protector 304-1 fromRFID tag 102(1)-1. This eliminates the short-circuit condition createdby conductive element 314 between first circuit element 312(1) andsecond circuit element 312(2) by removing the short-circuit linkage. Ifoperability input 316 of IC 104 is not forced to ground, IC 104 iscapable of responding to an interrogation signal that is received viaantenna 106 and RFID tag 102(1)-1 is in an active state.

The example RFID tag implementations for on-demand activation of RFIDtags that are described above and illustrated in FIG. 3-1 establish aninactive state by instituting a short-circuit condition between anoperability input 316 of IC 104 and a ground node 318. In contrast,example RFID tag implementations for on-demand activation of RFID tagsthat are described below and illustrated in FIG. 3-2 establish aninactive state by instituting a short-circuit condition between anantenna end 206 of antenna 106 and a ground node 318.

FIG. 3-2 depicts additional example RFID tag implementations foron-demand activation of RFID tags in accordance with one or moreembodiments. For example embodiments, RFID tag 102(1)-2 includes (i) anRFID substrate 202 having a first RFID substrate side 202(1) and asecond RFID substrate side 202(2) and (ii) a removable temporaryadhesive protector 304-1. Second RFID substrate side 202(2) includes anantenna 106 having a first antenna end 206(1) and a second antenna end206(2). First RFID substrate side 202(1) includes an IC 104, at leastone adhesive portion 310, at least one circuit element 312 that is partof activation circuitry 302 (e.g., of FIG. 3), a ground node 318, and aconnective circuit element 320. IC 104 includes a first antenna terminal204(1) and a second antenna terminal 204(2), as well as a terminal toground node 318. At least one circuit element 312 may include a firstcircuit element 312(1) and a second circuit element 312(2). Temporaryadhesive protector 304-1 includes conductive element 314.

In example operative embodiments, first antenna end 206(1) is coupled tofirst antenna terminal 204(1) of IC 104, and second antenna end 206(2)is coupled to second antenna terminal 204(2) of IC 104. First circuitelement 312(1) is a circuit element that is coupled (e.g., viaconnective circuit element 320) to first antenna terminal 204(1) of IC104 and first antenna end 206(1). Second circuit element 312(2) is agrounded circuit element that is coupled to ground node 318. For aninactive state of RFID tag 102(1)-2 in which IC 104 is incapable ofresponding to an interrogation signal 112 (e.g., of FIG. 1), temporaryadhesive protector 304-1 is flipped over and positioned (i) such thattemporary adhesive protector 304-1 covers adhesive portion 310 (e.g.,adhesive portion 310 on the left side of first RFID substrate side202(1) of FIG. 3-1) and (ii) such that conductive element 314 contactsfirst circuit element 312(1) and second circuit element 312(2).

If temporary adhesive protector 304-1 is attached to RFID tag 102(1)-2,a short-circuit condition is established between first circuit element312(1) and second circuit element 312(2) with a short-circuit linkagecreated by conductive element 314. This short-circuit condition couplesfirst antenna end 206(1) (and first antenna terminal 204(1) of IC 104)to ground node 318. In this implementation, grounding antenna 106effectively prevents receipt of an interrogation signal or effectivelydisables wireless energization of RFID tag 102(1)-2. Even if aninterrogation signal arrives at RFID tag 102(1)-2 from an RFID reader,IC 104 is incapable of responding to the interrogation signal. If aperson is ready to activate RFID tag 102(1)-2, the person may detachtemporary adhesive protector 304-1 from RFID tag 102(1)-2. Thiseliminates the short-circuit condition created by conductive element 314between first circuit element 312(1) and the grounded second circuitelement 312(2) by removing the short-circuit linkage. If first antennaend 206(1), and first antenna terminal 204(1) of IC 104 that is coupledthereto, is not forced to ground, IC 104 is capable of responding to aninterrogation signal that is received via antenna 106 and RFID tag102(1)-2 is in an active state.

FIG. 3-3 depicts additional example RFID tag implementations foron-demand activation of RFID tags in accordance with one or moreembodiments. As illustrated, RFID tag 102(1)-3 includes, like RFID tag102(1) of FIG. 3, an RFID substrate 202, an IC 104, an antenna 106,activation circuitry 302, and a disable tab 304. RFID tag 102(1)-3further includes a timer 330 and a weight sensor 332. For exampleembodiments, an RFID tag 102 may include a timer 330 or a weight sensor332. Timer 330 is shown integrated with IC 104, and weight sensor 332 isshown being coupled thereto. However, the timer 330 or the weight sensor332 may be integrated with or discrete from an IC 104.

For an example RFID tag 102(1)-3 implementation that includes a timer330, the timer 330 may keep track of real-world clock time (or time anddate) once programmed with a current time or date, may track elapsedtime once started, may track countdown time once started, or acombination thereof. Time tracking, such as counting upward for elapsedtime or downward toward an expiration time, may be started as part of amanufacturing process of RFID tag 102(1)-3, may be started in responseto a received interrogation signal—which triggering signal may includean instruction or command to start a timer, may be started responsive todisable tab 304 being detached from RFID tag 102(1)-3, some combinationthereof, and so forth.

Timer 330 may include a time value that affects if or how IC 104 mayrespond to an interrogation signal. In other words, an existence, acontent, a timing, etc. of a response by an IC 104 may be based at leastpartially on a parameter that is derived from a time value of timer 330.Examples of a parameter include a current value of a timer, an alertthat depends on a time value, an expiration indication, a differencebetween a current time value and a perishable period, or somecombination thereof. For example, IC 104 may report a current time valuein response to an interrogation signal, IC 104 may respond if a timevalue is changing (i.e., if a timer 330 has been started) but nototherwise, IC 104 may respond with an alert if a certain amount of timehas transpired (e.g., if a countdown timer has expired or if a count-uptimer reaches one or more or threshold levels), or some combinationthereof.

For an example usage scenario, disable tab 304 of RFID tag 102(1)-3 maybe de-attached if an item is opened or if a container is supplied with aperishable product. Afterwards, if a perishable period has expired, RFIDtag 102(1)-3 may respond to an interrogation signal with a warningindication. If a perishable period has not transpired, RFID tag 102(1)-3may respond with an “ok,” may respond with an indication of a remainingsafe time, or may elect to not respond to an interrogation signal. IC104 may be manufactured with at least one value representative of aperishable period, or RFID tag 102(1)-3 may be programmed with aperishable period wirelessly.

For an example RFID tag 102(1)-3 implementation that includes a weightsensor 332, weight sensor 332 may measure/detect a weight of an objectto which RFID tag 102(1)-3 is secured an output an indication of thedetected weight. In other words, an existence, a content, a timing, etc.of a response by an IC 104 may be based at least partially on aparameter that is derived from a weight value. Examples of a parameterinclude a current value of a weight sensor, a notification that dependson a current weight value, a difference between a current weight valueand an original or first weight value, an indication of time remaininguntil product weight becomes negligible—e.g. based on a rate ofreduction of weight, or some combination thereof. IC 104 may beconfigured to track changes in the weight of an object over time or toat least provide a weight value representative of a current weight.

For an example usage scenario, in response to receiving an interrogationsignal, RFID tag 102(1)-3 may be configured to send an indication ofremaining product (e.g., cereal, milk, eggs, flour, pills, or liquidmedicine) in a package with which it is associated, such as beingincorporated into or adhered to the packaging. Example indications ofremaining product may include values representative of ounces,percentage remaining or used, “full,” one-quarter consumed, product notneeded currently, more product needed, an integer quantity used orremaining, an expected time period until a remaining product is consumedbased on a historical rate of consumption, or a combination thereof.

The example RFID tag implementations for on-demand activation of RFIDtags that are described herein above and illustrated in FIGS. 3-1 and3-2 establish an inactive state by instituting a short-circuit conditionbetween a ground node and another node of RFID tags 102(1)-1 and102(1)-2. Alternatively, a disable tab 304 may establish an inactivestate by instituting an open-circuit condition in activation circuitry302 of an RFID tag 102. For example, a disable tab 304 may include aninsulating element having a non-conductive portion (e.g., made ofplastic) that is disposed between two conductive contacts of activationcircuitry 302 of an RFID substrate 202 to establish an inactive state ofRFID tag 102. If disable tab 304 is detached from RFID tag 102, the twoconductive contacts are permitted to touch (e.g., under a spring-like ortension mechanism) to complete a circuit that establishes an activestate for RFID tag 102 to enable an IC 104 and an antenna 106 to receiveand respond to an interrogation signal.

FIGS. 4 and 5 illustrate example methods for on-demand RFID tagactivation in accordance with one or more embodiments. The order inwhich the methods are described is not intended to be construed as alimitation, and any number or combination of the described methodoperations can be performed in any order or with any amount of temporaloverlap to perform a method, or an alternate method.

For flow diagram 400 of FIG. 4, operations 402-404 may be performed by aperson. At block 402, a disable tab that is attached to an RFID tag thatincludes an integrated circuit coupled to an antenna is grasped, withthe RFID tag being in an inactive state in which the integrated circuitis incapable of responding to a received interrogation signal if thedisable tab is attached to the RFID tag. For example, a person may graspa disable tab 304 that is attached to an RFID tag 102(1) that includesan IC 104 coupled to an antenna 106, with RFID tag 102(1) being in aninactive state in which IC 104 is incapable of responding to a receivedinterrogation signal 112 if disable tab 304 is attached to (e.g., andproviding a short-circuit current path to ground in activation circuitryof or instituting an open-circuit condition in activation circuitry of)RFID tag 102(1).

At block 404, the disable tab is detached from the RFID tag to establishan active state of the RFID tag in which the integrated circuit iscapable of responding to a received interrogation signal. For example, aperson may detach disable tab 304 from RFID tag 102(1) to (e.g.,eliminate a short-circuit current condition between a circuit node andground to thereby) establish an active state of RFID tag 102(1) in whichIC 104 is capable of responding to a received interrogation signal 112(e.g., by formulating and sending a response signal 114).

For flow diagram 500 of FIG. 5, operations 502-508 may be performed byan RFID tag 102. Methods or operations described herein can beimplemented using hardware in conjunction with software, firmware, fixedlogic circuitry, a combination thereof, and so forth. Some operations ofthe example methods may be described in a general context ofprocessor-executable instructions that are stored onprocessor-accessible (e.g., computer-readable) storage memory that ispart of an RFID tag 102 (e.g., that is disposed on an RFID substrate 202as part of, or separate from, an IC 104).

At block 502, detachment of a disable tag from an RFID tag, whichincludes an integrated circuit and an antenna, is detected. For example,an RFID tag 102(1) may detect that a disable tab 304 is detached (e.g.,partially or fully) from RFID tag 102(1) (e.g., because an open-circuitcondition or a short-circuit condition that was preventing at least someof the functionality of the RFID tag—such as an ability to respond to aninterrogation signal—is eliminated and wireless functionality isinitiated), which RFID tag 102(1) includes an IC 104 and an antenna 106.

At block 504, responsive to detection of the detachment of the disabletag from the RFID tag, a timer of the integrated circuit is started. Forexample, if RFID tag 102(1) detects that disable tab 304 is detachedtherefrom, a timer 330 of IC 104 may be started (e.g., a time value maybe incremented or decremented at a known rate). For instance, a timer330 may start counting down from a time value that is initially set tocoincide with a perishability period, such as a recommended use-by dateor use-within time period.

At block 506, an interrogation signal is received via the antenna of theRFID tag. For example, RFID tag 102(1) may receive an interrogationsignal 112 via antenna 106. At block 508, responsive to receipt of theinterrogation signal, a parameter derived from a value of the timer issent via the antenna of the RFID tag. For example, based on anenergization by or an inquiry of interrogation signal 112, a parameterderived from a value of timer 330 may be sent (e.g., modulated RFbackscatter that is returned, encoded electromagnetic radiation that isreflected, or transmitted) via antenna 106 of RFID tag 102(1). Forinstance, a remaining time for safe consumption of a perishable product(e.g., a result of subtracting a value of timer 330 from a stored orreceived perishable period) or a “safe/unsafe” notification may be sentas at least part of a response signal 114.

FIG. 6 illustrates an example RFID tag 102(2) for implementations ofperson-centric RFID tag activation in accordance with one or moreembodiments. As illustrated in logical or block diagram form, exampleRFID tag 102(2) includes an RFID substrate 202, an IC 104, an antenna106, and skin proximity activation circuitry 602. IC 104 is coupled toantenna 106 or skin proximity activation circuitry 602; antenna 106 iscoupled to IC 104 or skin proximity activation circuitry 602; and skinproximity activation circuitry 602 is coupled to IC 104 or antenna 106.

For example embodiments, activation of RFID tag 102(2) is at leastpartially dependent on a proximity to skin 604 (e.g., human epidermis).RFID tag 102(2) is in an inactive state if RFID tag 102(2) is notproximate to skin 604, but RFID tag 102(2) is in an active state if RFIDtag 102(2) is proximate to skin 604. Skin proximity activation circuitry602, based at least partially on a determination of proximity of RFIDtag 102(2) to skin 604, places RFID tag 102(2) in, or causes RFID tag102(2) to be in, an active state or an inactive state. As discussedfurther herein below, an RFID tag 102(2) that is in an active state maybe in an operationally active state or in a communicatively activestate.

An RFID tag 102(2) may be proximate to skin 604, for example, if RFIDtag 102(2) is in physical contact with skin 604, if RFID tag 102(2) istouching skin 604, if RFID tag 102(2) is capable of using skin 604 tocomplete a circuit (e.g., if skin proximity activation circuitry 602 iscompleted by passing a signal thru skin 604), if RFID tag 102(2) iscapable of sensing a person's temperature through skin 604, if RFID tag102(2) senses a temperature that is within a human-appropriate bodytemperature range, or some combination thereof. Example implementationsin which a skin proximity determination is based at least partially onusing skin 604 to complete a circuit of skin proximity activationcircuitry 602 are described herein below with particular reference toFIG. 6-1. Example implementations in which a skin proximitydetermination is based at least partially on sensing a particulartemperature (e.g., through skin 604) as performed by skin proximityactivation circuitry 602 are described herein below with particularreference to FIG. 6-2. Example implementations that combine skin contactdetection with skin temperature detection to determine skin proximityare described herein below with particular reference to FIG. 6-3.

If RFID tag 102(2) is in an operationally active state, RFID tag 102(2)is configured to be capable of receiving, processing, or responding toan interrogation signal or configured to be able to determine if aresponse to an interrogation signal is to be sent. Exampleimplementations of an RFID tag 102(2) that may be placed in anoperationally active state or in an operationally inactive state (e.g.,based on skin proximity as detectable by physical contact) are describedherein below with particular reference to FIG. 6-1. If RFID tag 102(2)is in a communicatively active state, RFID tag 102(2) is configured tosend a response to an interrogation signal. Example implementations ofan RFID tag 102(2) that may be placed in a communicatively active stateor in a communicatively inactive state (e.g., based on skin proximity asdetectable by sensed temperature) are described herein below withparticular reference to FIG. 6-2. With regard to FIG. 6-3, skinproximity activation circuitry 602 may place an RFID tag 102(2) (i) intoan operationally active state from an operationally inactive state or(ii), while in an operationally active state, into a communicativelyactive state from a communicatively inactive state.

For one or more example embodiments, antenna 106 is configured toreceive an interrogation signal (e.g., an interrogation signal 112). IC104 is coupled to antenna 106. IC 104 is configured to process and torespond to the interrogation signal if RFID tag 102(2) is in an activestate, and IC 104 is configured to not respond to the interrogationsignal if RFID tag 102(2) is in an inactive state. Skin proximityactivation circuitry 602 is configured to establish the active state ifRFID tag 102(2) is proximate to skin 604 or to establish the inactivestate if RFID tag 102(2) is not proximate to skin. Exampleimplementations of skin proximity activation circuitry 602 are describedbelow with particular reference to FIGS. 6-1, 6-2, and 6-3.

FIG. 6-1 depicts additional example RFID tag implementations forperson-centric activation of RFID tags in accordance with one or moreembodiments. As illustrated, RFID tag 102(2)-1 is a schematic diagram ofan example RFID tag that is depicted as a medical implement.Specifically, RFID tag 102(2)-1 is shown as a bandage with centralizedprotective padding, which may include topical medicine, at least onesensor, and so forth. However, RFID tag 102(2)-1 (or RFID tag 102(2)-2and 102(2)-3 of FIGS. 6-2 and 6-3, respectively) may be realized asanother type of medical implement or as another object that is designedor intended to be attached to skin, such as an athletic performancemonitoring object.

For example embodiments, RFID tag 102(2)-1 includes an RFID substrate202 (e.g., also of FIG. 2) having a first RFID substrate side 202(1) anda second RFID substrate side 202(2). Opposite sides of an RFID substrate202 are shown as first RFID substrate side 202(1) and second RFIDsubstrate side 20(2). Certain components are shown on respective RFIDsubstrate sides to avoid visually obscuring relevant components orinterrelationships of the components. Although certain components areshown with respect to a particular substrate side, one or more of thecomponents may be on a same side, may be distributed across the twosides differently than is depicted, may be implemented fully orpartially within the substrate, some combination thereof, and so forth.

Second RFID substrate side 202(2) includes an antenna 106 having a firstantenna end 206(1) and a second antenna end 206(2). First RFID substrateside 202(1) includes an IC 104 and at least one skin contact point 610that is part of skin proximity activation circuitry 602 (e.g., of FIG.6), such as a first skin contact point 610(1) and a second skin contactpoint 610(2). IC 104 includes a first antenna terminal 204(1) and asecond antenna terminal 204(2).

In example operative embodiments, first skin contact point 610(1) iscoupled to first antenna end 206(1). Second antenna end 206(2) iscoupled to first antenna terminal 204(1) of IC 104. Second antennaterminal 204(2) of IC 104 is coupled to second skin contact point610(2). Second skin contact point 610(2) and first skin contact point610(1) may be coupled to skin 604 if RFID tag 102(2)-1 is positionedagainst a person.

Skin contact point 610 may comprise, for example, a wire tip, a wirepattern, one or more conductive traces, at least one conductive pad, anadhesive portion or area, or some combination thereof. A skin contactpoint 610 is adapted to establish an electrical connection or a signalcoupling between circuitry of RFID tag 102(2)-1 and skin 604 if a skincontact point 610 is positioned against (e.g., is physically touching ormakes contact with) skin 604. If two skin contact points 610, such as afirst skin contact point 610(1) and a second skin contact point 610(2),are positioned against skin 604, a skin circuit connection 620 may becreated between the two skin contact points 610. A skin circuitconnection 620 may be located within skin 604, along a surface of skin604, some combination thereof, and so forth.

For example implementations, a skin circuit connection 620 enables skinproximity activation circuitry 602 (e.g., of FIG. 6), which includes atleast first skin contact point 610(1) and second skin contact point610(2), to be completed. If skin proximity activation circuitry 602 iscompleted via first and second skin contact points 610(1) and 610(2)along with skin circuit connection 620, an antenna loop is completed forantenna 106 and for first antenna terminal 204(1) and second antennaterminal 204(2) of IC 104. If the circuitry of RFID tag 102(2)-1 iscompleted, RFID tag 102(2)-1 is operationally active and configured toreceive, process, or respond to an interrogation signal 112 (e.g., bysending a response signal 114).

To facilitate creating a skin circuit connection 620 that completes acircuit of RFID tag 102(2)-1, a resistance level of a length or area orvolume (along with any potential galvanic response) of skin 604 that isto extend between first skin contact point 610(1) and second skincontact point 610(2) may be considered. An expected (e.g. predicted,probable, or calculated) resistance value range for a skin circuitconnection 620 of skin 604 may be, by way of example only, approximately300 Ohms to 210K Ohms, with a likely range of 3K to 100K Ohms. Anexpected resistance value for skin 604 may vary based on any one or moreof a number of factors, such as water retention, body mass, skin drynessin conjunction with likelihood of or level of perspiration, distancebetween first and second skin contact points 610(1) and 610(2), width orarea of first and second skin contact points 610(1) and 610(2), and soforth. For instance, the above-provided example resistance values may beapplicable to a skin circuit connection 620 ranging from a fewmillimeters (mm) in length to 30 centimeters (cm) in length.

FIG. 6-2 depicts additional example RFID tag implementations forperson-centric activation of RFID tags in accordance with one or moreembodiments. For example embodiments, RFID tag 102(2)-2 includes an RFIDsubstrate 202 having a first RFID substrate side 202(1) and a secondRFID substrate side 202(2). Second RFID substrate side 202(2) includesan antenna 106 having a first antenna end 206(1) and a second antennaend 206(2). First RFID substrate side 202(1) includes an IC 104, atleast one adhesive portion 310, and at least one temperature sensor 630that is part of skin proximity activation circuitry 602 (e.g., of FIG.6). IC 104 includes a first antenna terminal 204(1) and a second antennaterminal 204(2), and IC 104 may also include at least one terminal forinterfacing with a separate sensor (e.g., temperature sensor 630). Asshown, first RFID substrate side 202(1) includes two adhesive portions310, but more or fewer may be included on either or both of first andsecond RFID substrate sides 202(1) and 202(2).

In example operative embodiments, first antenna terminal 204(1) of IC104 is coupled to first antenna end 206(1), and second antenna end206(2) is coupled to second antenna terminal 204(2) of IC 104. As shown,temperature sensor 630 is coupled to IC 104. Alternatively, temperaturesensor 630 may be integrated with IC 104. Also, temperature sensor 630may be disposed at a location different from that which is illustrated.In operation, temperature sensor 630 is adapted to sense or detect askin temperature of a person via physical contact, an infrared (IR)mechanism, some combination thereof, and so forth. Temperature sensor630 is configured to provide a temperature value representative of theskin temperature, and IC 104 is configured to obtain the temperaturevalue representative of the skin temperature from temperature sensor630.

A skin temperature may be representative of an actual surfacetemperature of skin 604, a body temperature of a person that is measuredat or through skin 604, some combination thereof, and so forth. IC 104may be configured to adjust a detected skin temperature obtained fromtemperature sensor 630 to account for a location on skin 604 at whichtemperature sensor 630 is sensing, to account for a mechanism used tosense a skin temperature, to account for a raw or proprietary valueprovided by temperature sensor 630, some combination thereof, and soforth. IC 104 may be configured to adjust a skin temperature, forexample, to convert the skin temperature (i) to a standard bodytemperature value for comparison purposes or (ii) prior to sending theskin temperature to an RFID reader 110. Alternatively, IC 104 may beconfigured to compare a raw skin temperature value to one or morethresholds or to send a raw skin temperature value that an RFID reader110 is programmed to adjust or otherwise utilize.

For example embodiments, skin proximity activation circuitry 602 (notexplicitly identified in FIG. 6-2) for RFID tag 102(2)-2 may includetemperature sensor 630 and at least part of IC 104. A state of RFID tag102(2)-2, such as active or inactive, may be established based at leastpartly on a proximity to skin 604 that is determined responsive to asensed temperature. For example, if a sensed temperature is above alower temperature threshold or below an upper temperature threshold orwithin a specified range of temperatures, RFID tag 102(2)-2 may beplaced in an active state.

More specifically, a state of RFID tag 102(2)-2 may comprise acommunicatively active state or a communicatively inactive state,depending on a sense temperature. If a sensed temperature is within aperson-appropriate temperature range, RFID tag 102(2)-2 may be placed ina communicatively active state in which a received and processedinterrogation signal is responded to by sending a response signal. Onthe other hand if a sensed temperature is not within aperson-appropriate temperature range, RFID tag 102(2)-2 may be placed ina communicatively inactive state in which an interrogation signal, evenif received and processed, is not responded to by sending a responsesignal.

A person-appropriate range of temperatures may comprise a range oftemperatures or an upper and a lower threshold temperature that istypical of a living person that is healthy or that is unhealthy,depending on context or usage scenario. A full person-appropriate rangemay extend between, for example, approximately 33.2° C. (91.8° F.) and41.5° C. (106.7° F.). Other approximate person-appropriate ranges mayinclude, for example: [1] a hypothermia range: below <33.2° C. (91.8°F.); [2] a normal range: 33.2° C. (91.8° F.)-38.2° C. (100.8° F.); [3] afever range: 38.3° C. (100.9° F.)-41.5° C. (106.7° F.); or [4] somecombination thereof. An upper temperature threshold or a lowertemperature threshold may be selected from any of these ranges.Additionally, other temperature ranges or temperature thresholds mayalternatively be implemented.

For a communicatively inactive state of RFID tag 102(2)-2, IC 104 may beoperationally active, but IC 104 is configured to not respond to aninterrogation signal 112. On the other hand, for a communicativelyactive state of RFID tag 102(2)-2, IC 104 is operationally active, andIC 104 is configured to respond to an interrogation signal 112 with acommunication. A communication response to an interrogation signal 112may include sending a response signal 114. A response signal 114 mayinclude an indication of a sensed temperature value, an indication of atime value (e.g., of an on-board timer indicative of how long a bandageor medicine thereof has been applied), an indication of another sensorvalue, a parameter derived from a sensed value or a time value, anidentification indication (e.g., a name or a patient number or code),some combination thereof, and so forth.

FIG. 6-3 depicts additional example RFID tag implementations forperson-centric activation of RFID tags in accordance with one or moreembodiments. RFID tag 102(2)-3 combines certain aspects of RFID tag102(2)-1 (e.g., of FIG. 6-1) and RFID tag 102(2)-2 (e.g., of FIG. 6-2).As illustrated, RFID tag 102(2)-3 includes an RFID substrate 202 (e.g.,also of FIG. 2) having a first RFID substrate side 202(1) and a secondRFID substrate side 202(2).

Second RFID substrate side 202(2) includes an antenna 106 having a firstantenna end 206(1) and a second antenna end 206(2). First RFID substrateside 202(1) includes an IC 104; at least one skin contact point 610 thatis part of skin proximity activation circuitry 602 (e.g., of FIG. 6),such as a first skin contact point 610(1) and a second skin contactpoint 610(2); at least one temperature sensor 630 that is part of skinproximity activation circuitry 602 (e.g., of FIG. 6); and at least oneother sensor 640. IC 104 includes a first antenna terminal 204(1) and asecond antenna terminal 204(2), and IC 104 may also include at least oneterminal for interfacing with a separate sensor (e.g., temperaturesensor 630 or other sensor 640).

Although depicted as being separate from IC 104 and temperature sensor630, other sensor 640 may be integrated with either or both. Althoughshown at particular locations, temperature sensor 630 or other sensor640 may be located at a different location, such as a centralizedpadding area, an adhesive area (e.g., an adhesive portion 310 of FIG.6-2), a skin contact area (e.g., a skin contact point 610), a locationthat overlaps multiple areas, and so forth. Also, temperature sensor 630or other sensor 640 may be co-located with or formed as part of a skincontact point 610.

Examples of other sensors 640 include a motion sensor (e.g., anaccelerometer or a gyroscope), an electrical activity sensor (e.g.,hospital EKG sensors), a heart-rate sensor, an ambient temperaturesensor, an oximetry sensor, a skin conductance sensor, other medicalsensors, or some combination thereof. An indication of a sensor value ofanother sensor 640, or a parameter derived therefrom, may be analyzed byIC 104 or sent as part of a response signal 114. A parameter that isderived from a sensor value may include an average sensor value, anormalized or compensated sensor value, an adjusted sensor value, adescription or categorization of a sensor value (e.g., “out-of-range,”“level 3,” “yellow,” “90-92,” “within acceptable range,” or acombination thereof), a label of a condition corresponding to a sensorvalue (e.g., “ok,” “danger,” “safe,” “needs attention,” or a combinationthereof), some combination thereof, and so forth.

In example operative embodiments, first skin contact point 610(1) iscoupled to first antenna end 206(1). Second antenna end 206(2) iscoupled to first antenna terminal 204(1) of IC 104. Second antennaterminal 204(2) of IC 104 is coupled to second skin contact point610(2). Second skin contact point 610(2) and first skin contact point610(1) may be coupled to skin 604 if RFID tag 102(2)-3 is positionedagainst a person. With such positioning, a skin circuit connection 620may be created between first and second skin contact points 610(1) and610(2). As illustrated, temperature sensor 630 is coupled to IC 104. Oneor more other sensors 640, if present, may also be coupled to IC 104 asshown.

In example implementations, RFID tag 102(2)-3 implements a two-phasemechanism for skin proximity activation circuitry 602. Initially, RFIDtag 102(2)-3 is in an inactive state—an operationally inactive and acommunicatively inactive state. IC 104 is neither receiving norprocessing interrogation signals 112 that arrive at RFID tag 102(2)-3.However, if a power source such as a battery or a capacitor is on-board,IC 104 may be taking sensor measurements and processing (e.g.,analyzing, organizing, or storing) them. In an example first phase, RFIDtag 102(2)-3 is positioned against skin 604. Skin circuit connection 620is created and an operational circuit is completed. RFID tag 102(2)-3establishes an operationally active state in which an interrogationsignal 112 may be received and processed by IC 104. However, IC 104 mayremain in a communicatively inactive state based on a skin temperaturedetected by temperature sensor 630.

For a second phase, establishment of a communicatively active stateversus a communicatively inactive state depends on a detectedtemperature. In response to receiving an interrogation signal 112, IC104 compares a sensed temperature value to a range of temperature values(e.g., to a lower temperature threshold or to an upper temperaturethreshold) to determine if the sensed temperature value comports withthe range of temperature values (e.g., to determine if the sensedtemperature value is above the lower temperature threshold or below theupper temperature threshold). If the sensed temperature value comportswith the range of temperature values, RFID tag 102(2)-3 is placed in acommunicatively active state in which IC 104 may elect to respond tointerrogation signal 112 by sending at least one response signal 114.Otherwise, RFID tag 102(2)-3 may remain in an operationally active statebut in a communicatively inactive state and may elect to not respond tointerrogation signal 112 with a responsive wireless signal.

FIGS. 7 and 8 illustrate example methods for person-centric RFID tagactivation in accordance with one or more embodiments. The order inwhich the methods are described is not intended to be construed as alimitation, and any number or combination of the described methodoperations can be performed in any order or with any amount of temporaloverlap to perform a method, or an alternate method.

For flow diagram 700 of FIG. 7, operations 702-704 may be performed by aperson. At block 702, at least one temporary cover is removed to exposea first skin contact point and a second skin contact point of a medicalimplement comprising an RFID tag that includes an integrated circuit andan antenna. For example, a person may remove at least one temporarycover (e.g., a temporary cover comparable to a temporary adhesiveprotector 304-1 of FIG. 3-1) to expose a first skin contact point 610(1)and a second skin contact point 610(2) of a medical implement (e.g., abandage or a sensor patch) comprising an RFID tag 102(2)-1 or 102(2)-3that includes an IC 104 and an antenna 106.

At block 704, the medical implement is pressed against a person to touchskin at the first skin contact point and at the second skin contactpoint to complete a circuit including the antenna and to render theintegrated circuit capable of responding to an interrogation signal. Forexample, a person may press the medical implement against a person(e.g., the same or a different person than is performing the pressing)to touch skin 604 at first skin contact point 610(1) and at second skincontact point 610(2) to complete a circuit (e.g., to create a skincircuit connection 620 between first and second skin contact points610(1) and 610(2) that enables operational activity of a circuit) thatincludes antenna 106 and to render IC 104 capable of responding to aninterrogation signal 112 (e.g., by sending a response signal 114).

For flow diagram 800 of FIG. 8, operations 802-808 may be performed byan RFID tag 102. Methods or operations described herein can beimplemented using hardware in conjunction with software, firmware, fixedlogic circuitry, a combination thereof, and so forth. Some operations ofthe example methods may be described in a general context ofprocessor-executable instructions that are stored onprocessor-accessible (e.g., computer-readable) storage memory that ispart of an RFID tag 102 (e.g., that is disposed on an RFID substrate 202as part of, or separate from, an IC 104).

Although not shown in flow diagram 800, one or more of the operationsthat are illustrated may further include or another operation mayinclude routing via skin a current signal for at least one of anintegrated circuit or an antenna of an RFID tag. For example, a currentsignal may be routed via a skin circuit connection 620 through skin 604for at least one of an IC 104 or an antenna 106 for an RFID tag 102(2)-3implementation of an RFID tag. At block 802, a skin temperature issensed to detect a temperature value. For example, a temperature sensor630 of an RFID tag 102(2)-2 or 102(2)-3 may sense skin temperature withrespect to skin 604 to detect a temperature value.

At block 804, the detected temperature value is compared to at least onetemperature threshold. For example, an IC 104 of RFID tag 102(2)-2 or102(2)-3 may compare the detected temperature value to an uppertemperature threshold or to a lower temperature threshold. For instance,IC 104 may determine if the detected temperature value is above thelower temperature threshold and below the upper temperature threshold.At block 806, an RFID interrogation signal is received. For example, IC104 may receive an interrogation signal 112 via an antenna 106 of RFIDtag 102(2)-2 or 102(2)-3.

At block 808, it is determined whether to respond to the RFIDinterrogation signal based on said comparing. For example, IC 104 maydetermine if RFID tag 102(2)-2 or 102(2)-3 is to respond tointerrogation signal 112 based at least partially on a comparisonincluding the detected temperature value and at least one temperaturethreshold. For instance, IC 104 may (i) elect not to send a responsesignal 114 if the detected temperature value is below a lowertemperature threshold and (ii) elect to wirelessly send response signal114 if the detected temperature value is above the lower temperaturethreshold. Additionally or alternatively, IC 104 may (i) elect not tosend response signal 114 if the detected temperature value is above theupper temperature threshold and (ii) elect to wirelessly send responsesignal 114 if the detected temperature value is below the uppertemperature threshold.

Although embodiments of on-demand activation of RFID tags andperson-centric activation of RFID tags have been described in languagespecific to features and/or methods, the subject of the appended claimsis not necessarily limited to the specific features or methodsdescribed. Rather, the specific features and methods are disclosed asexample implementations of on-demand RFID tag activation andperson-centric RFID tag activation, and other equivalent features andmethods are intended to be within the scope of the appended claims.Further, various different embodiments are described and it is to beappreciated that each described embodiment can be implementedindependently or in connection with one or more other describedembodiments.

1. A radio frequency identification (RFID) tag, comprising: an antennaconfigured to receive an interrogation signal; an integrated circuitcoupled to the antenna, the integrated circuit including an externaloperability input and configured to respond to the interrogation signalif the RFID tag is in an active state and not respond to theinterrogation signal if the RFID tag is in an inactive state; and adisable tab that is detachable from the RFID tag, the disable tabincluding a conductive element configured to disable activationcircuitry of the RFID tag and maintain the RFID tag in the inactivestate if the disable tab is attached to the RFID tag.
 2. The RFID tag asrecited in claim 1, wherein the activation circuitry includes a firstcircuit element coupled to the external operability input of theintegrated circuit and a second circuit element coupled to a ground nodeof the RFID tag.
 3. The RFID tag as recited in claim 2, wherein theconductive element of the disable tab provides a short-circuit betweenthe first circuit element and the second circuit element of theactivation circuitry if the disable tab is attached to the RFID tag. 4.The RFID tag as recited in claim 1, wherein the activation circuitry isconfigured to initiate the active state if the disable tab is detachedfrom the RFID tag.
 5. The RFID tag as recited in claim 1, wherein theRFID tag comprises at least a portion of a label.
 6. The RFID tag asrecited in claim 1, wherein the external operability input of theintegrated circuit comprises temperature of a user of the RFID tag ifthe disable tab is detached from the RFID tag and the active state isinitiated.
 7. The RFID tag as recited in claim 1, wherein the externaloperability input of the integrated circuit comprises a reset input ofthe integrated circuit.
 8. The RFID tag as recited in claim 1, wherein:the RFID tag further comprises a sensor configured to detect atemperature value and output the temperature value; and the integratedcircuit is configured to respond to the interrogation signal if the RFIDtag is in the active state by wirelessly providing a parameter that isderived from the temperature value.
 9. A method for on-demand activationof a radio frequency identification (RFID) tag, the method comprising:detecting that a disable tab is detached from the RFID tag, the RFID tagincluding an integrated circuit coupled to an antenna of the RFID tag,the RFID tag being in an inactive state in which the integrated circuitdoes not respond to a received interrogation signal with the disable tabattached to the RFID tag prior to the detecting that the disable tab isdetached from the RFID tag; establishing an active state of the RFID tagin response to the detecting that the disable tab is detached from theRFID tag; and detecting a temperature in the active state with the RFIDtag applied to an object; wirelessly providing temperature information,via the antenna, in response to receipt of the interrogation signal andthe RFID tag being in the active state.
 10. The method as recited inclaim 9, further comprising: maintaining the inactive state of the RFIDtag if the disable tab is not detached from the RFID tag.
 11. The methodas recited in claim 9, wherein the integrated circuit includes a timerconfigured to start in response to the detecting that the disable tab isdetached from the RFID tag, and said wirelessly providing thetemperature information as a temperature value responsive to receipt ofthe interrogation signal and the RFID tag being in the active state. 12.The method as recited in claim 11, wherein the RFID tag includes asensor to detect the temperature and output the temperature valuecorresponding to the temperature, and said wirelessly providing thetemperature information as the temperature value responsive to receiptof the interrogation signal and the RFID tag being in the active state.13. The method as recited in claim 9, wherein an external operabilityinput of the integrated circuit comprises the temperature of the objectthat has the RFID tag applied if the disable tab is detached from theRFID tag and the active state is initiated.
 14. The method as recited inclaim 9, wherein: the antenna includes a first antenna end coupled to afirst antenna terminal of the integrated circuit and a second antennaend coupled to a second antenna terminal of the integrated circuit; andthe RFID tag includes activation circuitry with a circuit elementcoupled to the first antenna end.
 15. The method as recited in claim 14,wherein: the activation circuitry further includes a grounded circuitelement; and the disable tab includes a conductive element configured toshort-circuit between the circuit element that is coupled to the firstantenna end and the grounded circuit element if the disable tab isattached to the RFID tag.
 16. The method as recited in claim 9, whereinthe disable tab includes an insulating element to institute an opencircuit preventing the integrated circuit from providing the temperatureinformation if the disable tab is attached to the RFID tag.
 17. A systemcomprising: a radio-frequency identification (RFID) reader configured towirelessly communicate an interrogation signal; a RFID tag comprising:an antenna that receives the interrogation signal; a disable tabimplemented for detachment from the RFID tag to activate the RFID tag,the disable tab detachable prior to the RFID tag being adhered to anobject; and an integrated circuit configured to wirelessly communicate,responsive to receipt of the interrogation signal from the RFID reader,information to the RFID reader via the antenna if the disable tab isdetached from the RFID tag, and the integrated circuit configured to notcommunicate if the disable tab is attached to the RFID tag.
 18. Thesystem as recited in claim 17, wherein the disable tab includes aconductive element to inactivate the integrated circuit if the disabletab is attached to the RFID tag.
 19. The system as recited in claim 17,wherein the RFID tag further comprises: a sensor to detect a temperatureand output a temperature value corresponding to the temperature; and theintegrated circuit is configured to wirelessly communicate thetemperature value as the information to the RFID reader responsive toreceipt of the interrogation signal from the RFID reader if the disabletab is detached from the RFID tag.
 20. The system as recited in claim17, wherein the RFID tag further comprises: a sensor to detect a weightof contents remaining in a package and output a weight valuecorresponding to the weight of the contents; and the integrated circuitis configured to wirelessly communicate the weight value as theinformation to the RFID reader responsive to receipt of theinterrogation signal from the RFID reader if the disable tab is detachedfrom the RFID tag.